UK compost
What compost for nasturtium 'empress of india' in the UK?
Tropaeolum majus 'Empress of India'
More about nasturtium 'empress of india' in the UK
Which compost nasturtium 'empress of india' needs
For nasturtium 'empress of india' the mix to buy is peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. Flowers most freely on poor to moderately fertile, well-drained soil at pH 6.0-7.5. Rich or heavily fed soil produces lush leaves and few blooms, so keep it lean.In British garden centres the bagged growing medium is sold simply as “compost” (multipurpose, ericaceous, or loam-based John Innes), which is a different thing from the rotted garden “compost” you make in a heap — for a pot you want the bagged kind.
Peat-free compost
Buy peat-free. The sale of peat compost to home gardeners is being phased out across the UK, and the RHS recommends peat-free on environmental grounds. A good peat-free multipurpose grows nasturtium 'empress of india' perfectly well; the one habit to change is watering — peat-free dries faster at the surface while still moist below, so check by feel a knuckle deep rather than trusting the look of the top.
Ericaceous or multipurpose?
Nasturtium 'Empress of India' does not want a rich, water-holding compost — it wants sharp drainage. Cut peat-free multipurpose roughly half-and-half with horticultural grit, sharp sand or perlite, and always pot into a container with drainage holes. A "cactus and succulent" bagged mix is a ready-made shortcut.
For the full recipe, pH and drainage detail (US wording), see the nasturtium 'empress of india' soil & potting-mix guide.
Compost for Nasturtium 'Empress of India' in the UK — frequently asked questions
What compost should I use for nasturtium 'empress of india' in the UK?
Use peat-free multipurpose compost cut roughly half-and-half with horticultural grit or perlite. Flowers most freely on poor to moderately fertile, well-drained soil at pH 6.0-7.5. Rich or heavily fed soil produces lush leaves and few blooms, so keep it lean. In UK garden centres this is sold simply as "compost" — the bagged growing medium, not garden-made leaf-mould — so match the description above rather than a brand.
Can I use ordinary multipurpose compost for nasturtium 'empress of india'?
Not on its own — multipurpose compost holds too much water for nasturtium 'empress of india' and will rot the roots. Cut it roughly 50:50 with horticultural grit, sharp sand or perlite so it drains fast.
Should the compost be peat-free?
Yes. Sales of peat compost to home gardeners are being phased out in the UK, and the RHS recommends peat-free for environmental reasons. Modern peat-free multipurpose composts grow nasturtium 'empress of india' perfectly well — they dry a little faster at the surface, so check moisture by feel rather than by the look of the top.
Does nasturtium 'empress of india' need grit or perlite added?
Yes — nasturtium 'empress of india' must have sharp drainage. Add about one part horticultural grit or perlite to one part compost, and always use a pot with drainage holes.
What pot and drainage does nasturtium 'empress of india' need?
Always a pot with drainage holes. Light, free-draining, poor-to-average soil. Stand it on a saucer, empty any water that collects after watering, and never leave the pot sitting in a full outer cover — waterlogged compost in a cool UK room is the commonest cause of root rot.
More nasturtium 'empress of india' care
See the full nasturtium 'empress of india' care guide, its UK watering and UK hardiness.